Plant growth regulator

ABSTRACT

A plant growth regulator comprising as an active ingredient a compound having a novel 2-sulfonyloxyethylphosphonic or -thionophosphonic acid skeleton of the formula   &lt;IMAGE&gt;   and a process for the production of the above compound.

This invention relates to a plant growth regulator comprising as an active ingredient a compound having a 2-sulfonyloxyethyl-phosphonic acid or 2-sulfonyloxyethyl-thionophosphonic acid skeleton of the following formula ##STR2## wherein X is O or S.

Many phenomena in plants induced by ethylene, a simple hydrocarbon, have been discovered since a report was made at the end of the nineteenth century that putrefaction of apples during storage was caused by ethylene. About 40 years ago, it was found that ethylene is biosynthesized as a natural plant metabolite, and its importance has been recognized as a new physiologically active substance which dominates the physiological phenomenon of plants. This led to a rapid advance in the investigation of the physiological activities of ethylene in plants, and consequently, ethylene came into use for regulating the growth of plants. However, because ethylene is gaseous at room temperature, its acceptance in agriculture has been limited. In use, ethylene must be included in a closed receptacle or applied indoors, and cannot be directly applied to fields. Furthermore, it is not free from a danger of fire or explosion.

Later, ethylene-releasing substances which generate ethylene after application and thus can regulate the growth of plants were discovered, and it was reported that these substances exhibit various physiological activities on the growth of plants. These substances are called a plant growth regulator, and effectively used in the following applications.

1. Breaking of dormancy

The plant growth regulator breaks the dormancy of strawberries, grapes, and flowering plant bulbs to cause germination and flowering uniformly.

2. Increased yield in the sap

The ethylene-generating substance is most widely used for increasing the amount of the latex of rubber trees, and can increase an effect of promoting sap formation to almost twice as much. Accordingly, by spraying the ethylene-generating substance to old rubber trees with reduced ability to secrete latex, their secreting power can be markedly increased.

3. Acceleration of flowering

By spraying the plant-growth regulator to bananas and pipeapple trees, they can be cultivated in successive years, and the promoting of flower-set and the increased yield of both plants are expected.

4. Sex reversal

Pistil adhesion of cucumber, pumpkin and watermelon can be increased by application of the plantgrowth regulator, and an increase in their yield can be expected. In particular, the adhesion of pistil is poor in greenhouse cultivation of cucumber because of temperature trouble, but this drawback can be avoided by the application of the plant growth regulator.

5. Promotion of the ripening period

The plant growthregulator promotes the ripening period of many fruit trees such as pears, persimmon, apple, orange, peach or fig. As compared with the case of not treating the trees with the plant growth regulator, the ripening fruits can be shipped 5 to 20 days earlier. Accordingly, this greatly affect the distribution of the labor on harvesting and the cost of the fruits on shipment, thus leading to an increased profit.

6. Promotion of coloration

The plant growth regulator promotes the yellowing of tabacco leaves, and the coloration of oranges, apples and peppers, and products of uniform color can be harvested.

7. Promotion of the falling leaves and fruits

The harvesting labor for picking leaves or fruits can be reduced by the application of the plant growth regulator. In particular, when it applied to woods and bushes, it promote the falling of the leaves of shrubs or broad-leaved vines, and this can replace the cutting of these leaves.

It has previously been known that β-hydroxyethyl hydrazine or its derivative can be utilized as a plant growth regulator, and has an effect of promoting the ripening of unripen fruits (Japanese Patent Publication No. 10748/69). It has also been known that compounds having a 2-chloroethylphosphonic acid skeleton can be utilized as a plant growth regulator (British Patent Specification No. 1194433). On the other hand, United States Patent 3,834,888 issued September 10, 1974 discloses that compounds of the formula ##STR3## wherein R¹ and R² are a substituted or unsubstituted hydrocarbon group, X is S or O, and A⁻ represents a non-phytotoxic anion,

are useful as plant growth regulators.

We found that compounds having a skeletal structure of the formula ##STR4## which are novel and not described in the prior literature exhibit superior plant growth regulating activities on a wide range of plants. For example, as will be shown hereinbelow by comparative examples, these compounds show superior results in plant growth regulating activity to 2-chloroethylphosphonic acid commercially available as a typical compound in the second prior art described above. Heretofore, the compounds having the above skeletal structure and their plant growth regulating activities have been completely unknown.

Accordingly, an object of this invention is to provide a superior plant growth regulator.

Another object of this invention is to provide a method for regulating the growth of plants using a compound having the above skeletal structure.

Still another object of this invention is to provide a process for preparing the above active compound.

The above and other objects and advantages of this invention will become more apparent from the following description.

The active ingredient of the plant growth regulating composition of this invention is a 2-sulfonyloxyethyl-phosphonic acid- or 2-sulfonyloxyethyl-thionophosphonic acid derivative of the formula ##STR5## wherein R₁ is a group selected from the class consisting of substituted or unsubstituted alkylgroups, substituted or unsubstituted alkenyl groups and substituted or unsubstituted aryl groups; R₂ and R₃ are identical or different and represent a member selected from the class consisting of the group --OR' in which R' is a member selected from the class consisting of a hydrogen atom, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups and substituted or unsubstituted aryl groups, the group --SR' in which R' is the same as defined above, the group --N(R')₂ in which R' is the same as defined above or represents a morpholino group including N of the above group, the two R' groups being identical or different, and halogen atoms; and X is S or O, with the proviso that when X is O and both R₂ and R₃ are the group --OR', at least one of the groups --OR' is --OH, and when X is S, both R₂ and R₃ are not the groups --N(R')₂ at the same time.

In the above formula (1), R₁ is preferably selected from the class consisting of substituted or unsubstituted C₁ to C₁₂ linear-, branched- or cyclo-alkyl groups, substituted or unsubstituted C₂ to C₁₂ linear-, branched-, or cyclo-alkenyl groups and substituted or unsubstituted C₆ to C₁₄ aryl groups. Specific examples of the preferred R₁ are C₁ to C₁₂ linear or branched alkyl groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, 2-methylpentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, or dodecyl, and C₅ to C₁₂ cycloalkyl groups such as cyclopentyl, cyclohexyl, cyclooctyl or cyclodecyl.

When R₁ is a substituted alkyl group, the substituent is preferably selected from the class consisting of halogen atoms, a cyano group, a nitro group, alkoxycarbonyl groups with the alkoxy moiety containing 1 to 12 carbon atoms, alkoxy groups containing 1 to 12 carbon atoms, a carboxyl group, acyl groups containing 1 to 12 carbon atoms, acyloxy groups containing 1 to 12 carbon atoms, a benzoyloxy group, a thiocyanate group, an isothiocyanate group, an acetamide group, a phthalimide group, an acetylthio group, a phosphono group, a sulfonyloxy group, a succinimide group, trialkylsilyl groups with the alkyl moiety containing 1 to 12 carbon atoms, aryl groups containing 6 to 14 carbon atoms, and alkylthio groups with the alkyl moety containing 1 to 12 carbon atoms. Specific examples of the preferred substituted alkyl groups include α-chloroethyl, γ-bromopropyl, γ-chloropropyl, γ,γ-dichloropropyl, chloromethyl, α-chlorocyclohexyl, β-cyanoethyl, β-methoxycarbonylethyl, β-ethoxycarbonylethyl, β-methoxycarbonylpropyl, γ-ethoxypropyl, γ-methoxypropyl, γ-phenoxypropyl, γ-ethoxyethyl, β-carboxyethyl, β-carboxypropyl, β-acetylethyl, γ-acetoxypropyl, β-acetoxyethyl, γ-benzoylpropyl, β-benzoylethyl, γ-nitropropyl, β-nitroethyl, β-nitro-α-phenylethyl, γ-thiocyanatopropyl, β-thiocyanatoethyl, γ-isothiocyanatopropyl, β-isothiocyanatoethyl, β-phthalimidoethyl, β-succinimidoethyl, β-acetamidoethyl, β-acetylthioethyl, β-phosphonoethyl, 2-(β-phosphonoethyloxysulfonyl)ethyl, (β-phosphonoethyloxysulfonyl) methyl, γ-trimethylsilylpropyl, β-trimethylsilylethyl, benzyl, and β-phenylethyl.

Specific examples of the preferred substituted branched alkyl group R₁ are 2-cyano-1-methylethyl, 2-chloro-1-methylethyl, 2-methoxyl,1-dimethylethyl, 5-methyl-7-nitroheptyl, and 4-carboxy-3-methylbutyl.

Specific examples of the preferred substituted cycloalkyl groups are 4-chlorocyclohexyl, 4-cyanocyclohexyl, 4-methoxycyclohexyl, 4-ethoxycyclohexyl, 4-carboxycyclohexyl, 2-nitrocyclohexyl, and 4-chlorocyclooctyl.

In the formula (1), the alkenyl group represented by R₁ includes, for example, C₂ to C₁₂ linear or branched alkenyl groups such as vinyl, propenyl, allyl, isopropenyl, butenyl, butadienyl, pentenyl, hexenyl, octenyl, and dodecenyl, and C₅ to C₁₂ cycloalkenyl groups such as cyclopentenyl, cyclopentadienyl, cyclohexenyl, and cyclodecenyl. The alkenyl groups containing 5 to 12 carbon atoms are especially preferred.

The substituent for the alkenyl group R₁ is preferably the same as those described with respect to the substituted alkyl groups.

Examples of the preferred substituted alkenyl groups are β-chlorovinyl, γ-chloropropenyl, γ-cyanopropenyl, γ-nitropropenyl, chloroisopropenyl, γ-phenoxypropenyl, β-carboxyvinyl, β-methoxycarbonylvinyl, β-benzylvinyl, styryl, γ-succinimidopropenyl, 65 -phthalimidopropenyl, γ-acetamidopropenyl, β-phosphonovinyl, and γ-trimethylsilylpropenyl.

The substituted cycloalkenyl group includes, for example, 4-chloro-2-cyclohexenyl or 4-carboxy-2-cyclohexenyl.

Examples of the aryl groups in formula (1) are phenyl, naphthyl, anthryl, phenanthryl, and biphenylyl. The substituent for the aryl groups includes, for example, an alkyl group containing 1 to 6 carbon atoms, a halogen atom, an acetyl group, an amido group, a nitro group, a cyano group, a carboxyl group, an alkoxy group containing 1 to 6 carbon atoms, a hydroxyl group, a sulfonyl group or a sulfo group. Specific examples of the substituted aryl groups in formula (1) are tolyl, xylyl, t-butylphenyl, cumenyl, chlorophenyl, bromophenyl, iodophenyl, acetylphenyl, acetamidophenyl, nitrophenyl, cyanophenyl, carboxyphenyl, methoxyphenyl, ethoxyphenyl, chloronitrophenyl, bromonitrophenyl, chlorotoyl, nitrotolyl, carboxytolyl, chloromethoxyphenyl, cyanotolyl, hydroxyphenyl, nitronaphthyl, chloroanthryl, cyanophenanthryl, and methoxybiphenyl.

Preferably, R₂ and R₃ in formula (1) are selected from the class consisting of the groups --OR' in which R' is a member selected from the class consisting of a hydrogen atom, substituted or unsubstituted C₁ to C₁₂ linear-, branched- or cyclo-alkyl groups, substituted or unsubstituted C₂ to C₁₂ linear-, branched- or cycloalkenyl groups and substituted or unsubstituted C₆ to C₁₄ aryl groups, the groups --SR' in which R' is the same as defined above, the groups --N(R')₂ in which R' is the same as defined above or morpholino including N of the above group, and the two R' groups are identical or different, and halogen atoms, especially chlorine. Examples of R' in the groups --OR', --SR' and --N(R')₂ are the same as those mentioned with regard to group R₁.

Examples of the group --OR' are hydroxyl, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, tert-butoxy, dodecyloxy, cyclohexyloxy, benzyloxy, chloroethyloxy, phenoxy, chlorophenoxy, tolyloxy, allyloxy, and chloroallyloxy. Examples of the group --SR' are mercapto, methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, tert-butylthio, dodecylthio, cyclohexylthio, benzylthio, chloroethylthio, phenylthio, chlorophenylthio, tolylthio, and allylthio.

Examples of the group --N(R')₂ are dimethylamino, isopropylamino, octylamino, dodecylamino, cyclopentylamino, cyclohexylamino, chloromethylamino, chloroethylamino, ethoxycarbonylmethylamino, cyanomethylamino, nitroethylamino, methoxymethylamino, chlorocyclohexylamino, phosphonomethylamino, phenylamino, tolylamino, cumenylamino, mesitylamino, xylylamino, chlorophenylamino, bromophenylamino, iodophenylamino, acetylphenylamino, acetamidephenylamino, aminophenylamino, naphtylamino, and morpholino groups.

Specific examples of the compounds of formula (1) are given below.

    ______________________________________                                         1. Compounds of formula (1-a)                                                         ##STR6##              (1)-a                                             Com-                                                                           pounds                                                                         No       R.sub.1               R'                                              ______________________________________                                         1     3-bromopropyl          methyl                                            2     chloromethyl           methyl                                            3     2-cyanoethyl           methyl                                            4     2-methoxycarbonylethyl methyl                                            5     2-methoxycarbonylethyl isopropyl                                         6     3-ethoxypropyl         methyl                                            7     3-ethoxypropyl         hydrogen                                          8     2-carboxyethyl         hydrogen                                          9     2-acetylethyl          hydrogen                                          10    3-acetoxypropyl        methyl                                            11    3-benzoyloxypropyl     methyl                                            12    2-nitroethyl           methyl                                            13    2-nitro-1-phenylethyl  methyl                                            14    3-thiocyanatopropyl    methyl                                            15    2-isothiocyanatoethyl  methyl                                            16    2-phthalimidoethyl     methyl                                            17    2-phthalimidoethyl     hydrogen                                          18    2-acetamidoethyl       methyl                                            19    2-acetylthioethyl      methyl                                            20    2-phosphonoethyl       hydrogen                                          21                                                                                    ##STR7##              hydrogen                                          22                                                                                    ##STR8##              hydrogen                                          23    (CH.sub.3).sub.3 SiCH.sub.2CH.sub.2                                                                   hydrogen                                          24    benzyl                 hydrogen                                          25    2-carboxyethyl         butyl                                             26    2-carboxyethyl         dodecyl                                           27    2-carboxyethyl         2-chloroethyl                                     28    2-carboxyethyl         phenyl                                            29    2-cyanoethyl           benzyl                                            30    2-cyanoethyl           p-chlorophenyl                                    31    2,3-dichloropropyl     methyl                                            32    2,3-dibromopropyl      methyl                                            33                                                                                    ##STR9##              methyl                                            34    vinyl                  methyl                                            35    allyl                  methyl                                            36    cyclohexenyl           methyl                                            37                                                                                    ##STR10##             methyl                                            38    methyl                 hydrogen                                          39    methyl                 ethyl                                             40    n-butyl                hydrogen                                          41    methyl                 methyl                                            42    phenyl                 hydrogen                                          43    p-tolyl                hydrogen                                          44    p-tolyl                ethyl                                             45    p-chlorophenyl         hydrogen                                          46    p-nitrophenyl          hydrogen                                          ______________________________________                                    

    __________________________________________________________________________     (2) Compounds of formula (1-b)                                                  ##STR11##                (1-b)                                                Compounds                                                                      Nos.    R.sub.1                                                                                R.sub.2     R.sub.3                                            __________________________________________________________________________     47    methyl  Cl          Cl                                                   48    p-tolyl Cl          Cl                                                   49    methyl  OH          OH                                                   50    2-carboxyethyl                                                                         OH          OH                                                   51    methyl                                                                                  ##STR12##                                                                                  ##STR13##                                           52    p-tolyl OH          OH                                                   53    methyl                                                                                  ##STR14##                                                                                  ##STR15##                                           54    methyl  OCH.sub.3   SC.sub.2 H.sub.5                                     55    methyl  OCH.sub.2CHCH.sub. 2                                                                       OCH.sub.2CHCH.sub.2                                  56    2-carboxyethyl                                                                         SCH.sub.2CH.sub. 2Cl                                                                       SCH.sub.2CH.sub.2Cl                                  __________________________________________________________________________

    __________________________________________________________________________     (3) Compounds of formula (1-c)                                                  ##STR16##                                                                     (excepting the case where R.sub.2 is OH, and R.sub.3 is OR')                   Compounds                                                                      Nos.    R.sub.1   R.sub.2    R.sub.3                                           __________________________________________________________________________     57    methyl                                                                                    ##STR17##                                                                                 ##STR18##                                          58    methyl                                                                                    ##STR19##                                                                                 ##STR20##                                          59    methyl    SCH.sub.3  SCH.sub.3                                           60    p-tolyl                                                                                   ##STR21##                                                                                 ##STR22##                                          61    p-chlorophenyl                                                                            ##STR23##                                                                                 ##STR24##                                          62    3-chloropropyl                                                                            ##STR25##                                                                                 ##STR26##                                          63    methyl    SH         SH                                                  64    methyl    OCH.sub.3  SC.sub.2 H.sub.5                                    65    p-tolyl   OCH.sub.3                                                                                  ##STR27##                                          66    p-chlorophenyl                                                                           OH                                                                                         ##STR28##                                          67    2-carboxyethyl                                                                           OCH.sub.2CHCH.sub.2                                                                       SCH.sub.3                                           68    methyl    OCH.sub.3  N(CH.sub.3).sub.2                                   69    2-carboxyethyl                                                                           OCH.sub.3  N(C.sub.2 H.sub.5).sub.2                            70    2-methoxycarbo-                                                                          OH         SCH.sub.3                                                 nylethyl                                                                 71    2-nitroethyl                                                                             SCH.sub.3  SCH.sub.3                                           72    vinyl     OCH.sub.3  SCH.sub.3                                           73    methyl    N(CH.sub.3).sub.2                                                                         N(CH.sub.3).sub.2                                   74    methyl                                                                                    ##STR29##                                                                                 ##STR30##                                          75    methyl    NHCH(CH.sub.3).sub.2                                                                      NHCH(CH.sub.3).sub.2                                76    methyl                                                                                    ##STR31##                                                                                 ##STR32##                                          77    methyl    N(CH.sub.3).sub.2                                                                          ##STR33##                                          78    n-butyl                                                                                   ##STR34##                                                                                 ##STR35##                                          79    2-chloroethyl                                                                             ##STR36##                                                                                 ##STR37##                                          80    chloromethyl                                                                             N(CH.sub.3).sub.2                                                                         N(CH.sub.3).sub.2                                   81    p-tolyl   NHCH(CH.sub.3).sub.2                                                                      NHCH(CH.sub.3).sub.2                                82    p-chlorophenyl                                                                           NHCH(CH.sub.3).sub.2                                                                      NHCH(CH.sub.3).sub.2                                83    methyl                                                                                    ##STR38##                                                                                 ##STR39##                                          84    iso-propyl                                                                               N(CH.sub.3).sub.2                                                                         N(CH.sub.3).sub.2                                   85    2-cyanoethyl                                                                             NH.sub.2   NH.sub.2                                            86    2-methoxyethyl                                                                           NHCH(CH.sub.3).sub.2                                                                      NHCH(CH.sub.3).sub.2                                87    methoxy   NH.sub.2   NH.sub.2                                            88    2-phosphonoethyl                                                                          ##STR40##                                                                                 ##STR41##                                          89    ethylthiomethyl                                                                           ##STR42##                                                                                 ##STR43##                                          90    p-acetamidophenyl                                                                        N(CH.sub.3).sub.2                                                                         N(CH.sub.3).sub.2                                   91    p-nitrophenyl                                                                            N(CH.sub.3).sub.2                                                                         N(CH.sub.3).sub.2                                   92    benzyl    N(CH.sub.3).sub.2                                                                         N(CH.sub.3 ).sub.2                                  93    2-nitroethyl                                                                              ##STR44##                                                                                 ##STR45##                                          __________________________________________________________________________

The 2-sulfonyloxyethyl-phosphonic acids or 2-sulfonyloxyethyl-thionophosphonic acids used in this invention can be easily prepared from 2-sulfonyloxyethyl-phosphonic acid diesters of the following formula ##STR46## wherein R₁ is the same as defined above, and R" is an alkyl group preferably having 1 to 4 carbon atoms, such as methyl, ethyl or isopropyl, a haloalkyl group preferably containing 1 to 4 carbon atoms, such as chloromethyl or 2-chloroethyl, or an alkenyl group containing 1 to 5 carbon atoms, such as an allyl group,

which are prepared by reacting known 2-hydroxyethylphosphonic acid diesters (for their synthesis, see, for example, Organic Reactions, 1951, Vol. 6, page 290) with corresponding sulfonyl halides.

The compounds of formula (2) are neither described in the literature, but can be obtained by a method similar to general known reactions for synthesizing sulfonic esters from alcohols. For example, they can be obtained by mixing 2-hydroxyethylphosphonic acid diesters with the corresponding sulfonyl halides under cooling in the presence of a base, for example, inorganic alkalies such as sodium carbonate, sodium hydroxide, potassium hydroxide or calcium hydroxide, and organic amines such as triethyl amine, trimethylamine, pyridine or lutidine. Usually, the reaction temperature is about -20° to about 40° C. and the reaction time is about 30 minutes to about 40 hours.

Some embodiments of synthesizing active compounds of formula (1) from sulfonyloxyethylphosphonic acid diesters of formula (2) will be described below.

1. Synthesis of compounds of formula (1-a)

These compounds of formula (1-a) are prepared by reacting phosphonic acid diesters of formula (2) with phosphorous pentachloride to form compounds of the following formula ##STR47## wherein R₁ is the same as defined above, and Y is Cl or --OR" in which R" is the same as defined above,

that is, compounds of the following formula (3) or (4) ##STR48## wherein R₁ and R" are the same as defined above, and reacting the resulting phosphonochloridates or phosphonic acid dichlorides of formula (3) or (4) with water, alcohols or phenols of the formula

    R'0H                                                       (5)

wherein R' is the same as defined above.

The reaction between the compound of formula (2) and phosphorus pentachloride can be carried out in the presence or absence of a solvent. Generally, it can be carried out at a temperature of about 0° C. to about 180° C., preferably room temperature to about 150° C. for a period of about 1 minute to about 5 hours, generally about 1 minute to about 2 hours, for example. Examples of the solvent that can be used in this reaction include halogenated hydrocarbons such as methylene chloride, chloroform or carbon tetrachloride, aromatic hydrocarbons such as toluene, benzene and xylene, and ethers such as diethyl ether or ethylene glycol dimethyl ether.

Preferably, the reaction of the compound of formula (3) or (4) with the compound of formula (5) is carried out in the presence of a solvent. The reaction proceeds more easily in the further presence of a basic compound. Thus, the reaction is preferably performed in the presence of a basic compound, for example, an inorganic alkali such as sodium hydroxide, potassium hydroxide or sodium carbonate, or an organic amine such as triethylamine, trimethylamine, lutidine or pyridine. The solvent may be the same as those exemplified with regard to the reaction of the compound of formula (2) with phosphorus pentachloride. Preferably, the reaction is carried out at a temperature of about -50° C. to about +100° C., preferably about -10° C. to about +25° C. The preferred reaction time is about 10 minutes to about 20 hours.

Compounds of formula (1-a) in which R' is hydrogen can be obtained also by other methods. For example, they can be easily obtained by reacting the phosphonic acid diesters of formula (2) with trialkylsilyl chlorides, for example, trimethylsilyl chloride, to form bistrimethylsilyl phosphonates of the following formula ##STR49## wherein R₁ is the same as defined above, and reacting the resulting compounds with water and/or lower alcohols with 1 to 4 carbon atoms such as methanol, ethanol or propanol. Usually, this reaction is carried out in the absence of a solvent. If desired, however, the same solvent as exemplified with regard to the reaction between the compound of formula (2) and phosphorus pentachloride can be used in this reaction, too. The reaction temperature is about -10° C. to about +70° C., preferably about 25° to about 40° C.

2. Synthesis of Compounds of Formula (1-b)

These compounds of formula (1-b) can be obtained by reacting the phosphonic acid dichlorides of formula (4) with phosphorus pentasulfide to form thionophosphonic acid dichlorides of the following formula ##STR50## wherein R₁ is the same as defined above, and reacting the resulting compounds with water, alcohols or phenols of formula (5) or thiols of formula (7)

    R'OH                                                       (5)

wherein R' is the same as defined above,

    R'SH                                                       (7)

wherein R' is the same as defined above.

Usually, the reaction of the phosphonic acid dichlorides of formula (4) with phosphorus pentasulfide is carried out in the absence of a solvent. If desired, however, it can also be carried out in the presence of a solvent, for example, an aromatic hydrocarbon such as toluene, xylene or cumene. Preferably, the reaction is carried out at a temperature of about 50° C., to about 200° C., especially about 120° C. to about 150° C. The reaction time is, for example, about 1 minute to about 15 hours, preferably about 5 minutes to about 2 hours.

The reaction of the resulting thionophosphonic acid dichlorides of formula (6) with the compounds of formula (5) or (7) can be performed, for example, for about 1 minute to about 50 hours at a temperature of preferably about -20° C. to about +150° C., more preferably about 0° C. to about 40° C. Since the reaction proceeds more easily in the presence of a basic compound, it is preferred to carry it out in the presence of a basic compound, for example, an inorganic alkali such as sodium carbonate, sodium hydroxide, potassium hydroxide, or calcium carbonate, or an organic amine such as triethylamine, trimethylamine, pyridine or lutidine. The reaction can be performed in the presence or absence of a solvent. Specific examples of the solvent are the same as those exemplified with regard to the reaction of the compounds of formula (2) with phosphorus pentachloride.

3. Synthesis of compounds of formula (1-c)

Of the compounds of formula (1-c), those of the following formula ##STR51## wherein R₁ and R' are the same as defined above, can be synthesized by reacting the phosphonochloridates of formula (3) with the thiols of formula (7) in the presence of basic compounds, or by reacting the phosphonic acid dichlorides of formula (4) with the thiols of formula (7) and the water, alcohols or phenols of formula (5) in the presence of bases. The basic compounds may be the same as the inorganic alkalies and organic amines exemplified above. The reaction temperature is preferably about -50° to about +100° C., especially about -20° to about +25° C. The reaction solvent and the reaction time may be the same as those described with regard to the reaction between the thionophosphonic acid dichlorides of formula (6) and the compounds of formula (7).

Of the compounds of formula (1-c), those having the following formula (1-c-B) ##STR52## wherein R₁ and R' are the same as defined above, can be synthesized by reacting the phosphonic acid dichlorides of formula (4) with the thiols of formula (7) under the same conditions as described with respect to the preparation of the compounds of formula (1-c-A).

Of the compounds of formula (1-c), those having the following formula (1-c-C) ##STR53## wherein R₁ and R' are the same as defined above, can be synthesized by reacting the phosphonoyl dichlorides of formula (4) with compounds of formula (8) ##STR54## wherein R' is the same as defined above and can represent a morpholino group including N,

which are primary or secondary amines, in the presence of basic compounds. Examples of the basis compounds are the same as those given hereinabove. The reaction conditions can be the same as those described with regard to the preparation of the compounds of formula (1-c-A).

The plant growth regulator composition of this invention usually consists of a growth regulating amount of the active compound of formula (1) and a gaseous, liquid or solid diluent, and can be used in any required formulation such as a wettable powder, emulsifiable concentrate, liquid preparation or paste. The amount of the active compound of formula (1) can be varied over a wide range of about 0.00001 to about 99% by weight, preferably 0.001 - 50%, and more preferably 0.005 - 10%, based on the weight of the plant growth regulator composition. Examples of such a diluent include liquid diluents such as water, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl cellosolve, diethylene glycol monoethyl ether, dimethyl sulfoxide, dimethyl formamide, isopropyl acetate, kerosene, benzene, toluene, or petroleum ether, gaseous diluents such as air, nitrogen, argon, propane, ethane or vinyl chloride, and solid diluents such as talc, diatomaceous earth, kaolinite, montmorillonite, attapulgite, wheat flour, and soybean flour.

According to this invention, there is provided a method for regulating the growth of plants, which comprises applying the compound of formula (1) to one or more parts of a plant, such as a stem, leaf, trunk, branch, fruit, seed, root or bud or to the locus in which the plant is growing or will be grown; or treating one or more part of a plant with the compound of formula (1).

The amount of the compound of formula (1) to be applied can be properly chosen according to the plant to be treated, the time of application, the intended regulating action, etc. Usually, the amount is about 10 to 4000 g, preferably about 20 to 2000g, per 10 ares of the locus in which the plant is growing or will be grown. When the compound is to be applied to a plant itself, for example, when it is applied to fruits or rubber trees, the amount is varied according to the surface area of the plant or the type of the compound of formula (1). Usually, a liquid composition containing the compound of formula (1) in a concentration of about 10 to 10,000 ppm is applied in an amount of about 2 to 100 ml. When the compound of formula (1) is applied by immersing one or more parts of a plant, for example, seeds, roots such as bulbs or seed potatoes, and buds in it, the intended regulating effect can be obtained by immersing them in a liquid composition containing the compound in a concentration of about 10 to 10,000 ppm for about 3 minutes to about 6 hours.

The active compound used in this invention is not limited to one species, but two or more kinds of the compound can be used in mixture. The plant growth regulator of this invention can also be used with fertilizers, insecticides, fungicides, herbicides and other plant growth regulators.

The following Examples illustrate the present invention.

EXAMPLES OF PREPARATION OF THE ACTIVE COMPOUNDS Example 1

3.9 g. of dimethyl 2-hydroxyethylphosphonate and 5.9 g of pyridine were dissolved in 40 ml. of dry diethyl ether, and the solution was cooled with ice to -5° C. A solution of 6.0 g of γ-bromopropylsulfonyl chloride in 30 ml. of dry diethyl ether was added dropwise to the cooled solution by means of a dropping funnel. After the addition, the mixed solution was allowed to stand for 24 hours at 0° to 5° C. The reaction mixture was poured into 50 ml. of 5% hydrochloric acid, and extracted with diethyl ether. The extract was dried over anhydrous sodium sulfate, and the solvent was distilled off at reduced pressure. The product was further dried at room temperature at 0.7 mmHg for 18 hours to afford dimethyl 2-(3-bromopropyl-sulfonyloxy)ethylphosphonate as a colorless oil in a yield of 75 mol %. The product showed the following characteristic values.

n_(D) ²² = 1.4960.

Nuclear magnetic resonance spectrum (CDCl₃): δ= 2.30 ppm (dt, 2H), 2.00 - 2.60 (m, 2H), 3.36 - 3.70 (m, 4H), 3.77 (D, 6H), 4.38 (dt, 2H). 2.0 g of the dimethyl-2-(3-bromopropyl-sulfonyloxy) ethylphosphonate was dissolved in 30 ml. of dry methylene chloride. 2.5 g of phosphorus pentachloride was added, and the mixture was refluxed for 1 hour. The solvent was distilled off at reduced pressure, and dry sulfur dioxide was passed into the residue, and the by products were distilled off under reduced pressure. 10 ml. of methylene chloride was added to form a solution, and water (1 ml) was added with ice cooling. The mixture was stirred for 20 minutes at room temperature, and the solvent was distilled off at reduced pressure. 20 ml. of acetone was added to form a solution. Activated carbon was added in a small amount to decolorize the solution and remove the remaining hydrogen chloride. The activated carbon was separated by filtration, and the solvent was disstilled off at reduced pressure. The residue was dried in vacuo to afford a colorless oil identified as Compound No. 1 which comes within the formula (1-a) given hereinabove. The yield was 83 mol %. The compound had the following characteristic value.

n_(D) ²³.5° C = 1.4935

By the same procedure as above, Compounds Nos. 2 to 4, 6 and 10 to 16, 18, 19, 31 to 33, 35 to 37 and 41 of formula (1-a) were prepared.

The characteristic values are as follows:

    ______________________________________                                         No. 3            N.sub.D.sup.23.5° C = 1.4800                           4                N.sub.D.sup.23.5° C = 1.4712                           6                N.sub.D.sup.23.5° C = 1.4673                           10               N.sub.D.sup.23.5° C = 1.4745                           11               N.sub.D.sup.23.5° C = 1.5149                           14               N.sub.D.sup.23.5° C = 1.5040                           16               m.p = 110 to 113° C.                                   41               n.sub.D.sup.20° C = 1.4609                             ______________________________________                                    

Example 2

2.0 g of dimethyl 2-(2-methoxycarbonylethylsulfonyloxy) ethylphosphonate was placed in a reactor purged with dry nitrogen, and with stirring at 140° C., 4.8 g of phosphorus pentachloride was added. After reacting them for 10 minutes, the reaction mixture was cooled to room temperature. Dry sulfur dioxide gas was passed into the mixture, and the by-products were distilled off at reduced pressure. 10 ml. of methylene chloride was added to form a solution, and then 1.25 g (equivalent) of dodecyl alcohol was added dropwise. The mixture was further cooled to -10° C., and 0.53 g of pyridine was added dropwise with stirring. After allowing the mixture to sgand for one day, the resulting crystals were separated by filtration at reduced pressure. With cooling, water in an amount exceeding the equivalent weight was added to the mother liquor. The mixture was stirred at room temperature for 2 hours, and the solvent was distilled off at reduced pressure. 10 ml. of water was added to the residue to form a solution. Then, activated carbon was added to decolorize the solution, followed by filtration. The mother liquor was concentrated at reduced pressure, and dried in vacuo to form a colorless liquid identified as Compound No. 26 of formula (1-a). The yield was 30 mol %. The compound showed the following characteristic values.

IR spectrum: 3400 cm⁻¹, 2260, 1700, 1350, 1160, 1040, 950

By the same procedure as above, Compounds Nos. 25, 27, 28, 29, and 30 were obtained.

Example 3

60 g of diethyl 2-hydroxyethylphosphonate and 4.2 g of triethylamine were dissolved in 75 ml. of dry diethyl ether, and the solution was cooled to -5° C.

4.45 g of methanesulfonyl chloride was dissolved in 75 ml. of dry diethyl ether, and the solution was added dropwise with stirring to the above cooled solution by means of a dropping funnel equipped with a side tube. After the addition, the temperature of the solution was returned to room temperature, and the solution was stirred for an additional 5 hours. The reaction mixture was concentrated at reduced pressure, and again diethyl ether was added. The insoluble matter was separated by filtration. The ethereal phase was washed with water, and dried, and the solvent was distilled off. The residue was dried at 0.7 mmHg at room temperature to afford a colorless oily substance. Thus, ##STR55## was obtained in a yield of 80 mol %. The product was clearly characterized by the following spectra.

IR spectrum: 1250 cm⁻¹ (characteristic absorption of P═O); 1030 cm⁻¹, 960 cm⁻¹ (characteristic absorption of P--O--C); 1360 cm⁻¹, 1175 cm⁻¹ (--O--SO₂ -- characteristic absorption).

NMR spectrum (solvent, CD₃ OD/CDCl₃ =1/7 volume ratio): δ=1.34 ppm (t, 6H), 2.30 (dt, 2H), 3.05 (s, 3H), 4.14 (dq, 4H), 4.45 (dt, 2H).

Mass spectrum: P (parent peak) = 260

A two-necked flask purged with dry argon was charged with 2.14 g of diethyl 2-methanesulfonyloxyethylphosphonate and 3.38 g of phosphorus pentachloride, and with stirring, they were heated to 110° C. Then, the temperature was raised to 150° C., and the mixture was maintained at this temperature for 20 minutes. The reaction mixture was then cooled to room temperature, and dry sulfur dioxide gas was passed into the mixture to oxidize the unreacted phosphorus pentachloride. The by-products were distilled off at reduced pressure, and 20 ml. of diethyl ether was added to dissolve the resulting product. Water in an amount exceeding the equivalent weight was added dropwise to the resulting solution with stirring. The solvent was distilled off at reduced pressure, and the residue was dried at 0.7 mmHg at room temperature to afford white crystals. The crystals were recrystallized from a solvent consisting of chloroform and acetone in a 1:1 volume ratio. Compound No. 38 was obtained as colorless crystals having a melting point of 116.5° to 117° C. in a yield of 67 mol %.

The product was clearly characterized by the following spectra.

IR spectrum: 2280 cm⁻¹, 1650 cm⁻¹ ##STR56## characteristic absorption; 1020 cm⁻¹, 970 cm⁻¹ (P--O characteristic absorption); 1350 cm⁻¹, 1140 cm⁻¹ (--O--SO₂ -- characteristic absorption).

NMR spectrum (solvent, CD₃ OC/CDCl₃ =1/7 volume ratio): δ=2.26 ppm (dt, 2H), 3.10 (s, 3H), 4.44 (dt, 2H), 5.36 (s, 2H).

Elemental analysis:

    ______________________________________                                                    C     H       O       P     S                                       ______________________________________                                         Calculated (%):                                                                             17.65   4.44    47.03 15.17 15.71                                 Found (%):   18.18   4.39    46.98 15.20 15.50                                 ______________________________________                                    

By the same procedure as above, Compounds Nos. 40, 42, 43, 45 and 46 of formula (1-a) were prepared. The characteristic values of these compounds were as follows:

    ______________________________________                                         Compounds                                                                      Nos.        Properties                                                         ______________________________________                                         40        m.p. = 88 to 89° C.                                           43        m.p. = 131 to 132° C.                                         45        m.p. = 122 to 123.5° C.                                       46        m.p. = 143 to 146° C.                                         42        NMR spectrum (CD.sub.3 OD/CDCl.sub.3 = 1/7):                                   δ = 2.20 ppm (dt, 2H), 4.30                                              (dt, 2H), 5.86(s, 2H),                                                         7.27 to 8.05 (m, 5H)                                                 ______________________________________                                    

Example 4

2.6 g of dimethyl 2-(3-ethoxypropylsulfonyloxy) ethylphosphonate was placed in a reactor purged with dry nitrogen, and with stirring at 140° C. 4.5 g of phosphorus pentachloride was added. After reacting for 10 minutes, the reaction mixture was cooled to room temperature, and a gas of dry sulfur dioxide was passed into the mixture. The resulting by-products were distilled off at reduced pressure. The residual oil was dissolved in 10 ml. of methylene chloride, and then water (1 ml.) was added with ice cooling. The mixture was stirred at room temperature for 20 minutes, and the solvent was distilled off at reduced pressure. 10 ml. of water was added to form a solution, and activated carbon was added in a small amount to decolorize the solution and remove the remaining hydrogen chloride. The activated carbon was separated by filtration, and the solvent was distilled off at reduced pressure. The product was further dried in vacuo to afford a colorless oil identified as Compound No. 7 of formula (1-a) in a yield of 62 mol%. This compound exhibited a refractive index (n_(D) ²³.5° C) of 1.4805.

By the same procedure as above, Compounds Nos. 8, 9, 17, and 20 to 24 of formula (1-a) were prepared.

The characteristic values of these compounds were as follows:

    ______________________________________                                         Compounds Nos.  Properties                                                     ______________________________________                                          8              m.p. = 145 to 148° C.                                   17              m.p. = 111 to 117° C.                                   24              m.p. = 114.5 to 120° C.                                 ______________________________________                                    

Example 5

3.0 g of diethyl 2-methanesulfonyloxyethylphosphonate obtained in the same way as in Example 3 and 2.4 g of phosphorus pentachloride were dissolved in 20 ml. of dry toluene, and the solution was heated under reflux for 2.5 hours at atmospheric pressure. Then, dry sulfur dioxide was passed into the reaction mixture the oxidize the unreacted phosphorus pentachloride. The solvent and by-products were distilled off at reduced pressure. To the resulting oily substance, 20 ml. of diethyl ether was added. Water in an amount exceeding the equivalent weight was added to the solution with stirring. The solvent was distilled off at reduced pressure, and the residue was dried at 0.7 mmHg and at room temperature to afford a colorless oil which was identified as Compound No. 39. The yield was 97 mol%. The product was clearly characterized by the following spectra.

IR spectrum: 2610 cm⁻¹, 2280 cm⁻¹ (characteristic absorption of ##STR57## 1660 cm⁻¹ (characteristic absorption of 950 to 1040cm⁻¹ (P-O characteristic absorption); 1360 cm⁻¹ 1180 cm⁻¹ (--O--SO₂ -- characteristic absorption).

NMR spectrum (solvent, CD₃ OD/CDCl₃ =1/7 volume ratio): δ = 1.35 ppm (t, 3H), 2.30 (dt, 2H), 3.09 (s, 3H), 4.11 (dq, 2H), 4.47 (dt, 2H), 5.84 (s, 1H).

Mass spectrum: P=232.

by the same procedure as above, Compound No. 44 of formula (1-a) was prepared. The IR spectrum of this compound was as follows:

2980 cm⁻¹, 2280, 1595, 1360, 1190, 1175, 1040 to 1000, 950.

EXAMPLE 6

Dimethyl 2-vinylsulfonyloxyethylphosphonate was prepared in the same way as in Example 1 from 3.8 g of dimethyl 2-hydroxyethylphosphonate, 1.9 g of pyridine and 4.0 g of 2-chloroethylsulfonyl chloride. The yield was 20 mol%. The NMR spectrum (CDCl₃) of this product was as follows:

δ=2.30 ppm (dt, 2H), 3.78 (d, 6H), 4,32 (dt, 2H), 6.1 to 6.6 (m, 3H).

Compound No. 34 of formula (1-a) was prepared in the same way as in Example 1 from 2.44 g of dimethyl 2-vinylsulfonyloxyethylphosphonate and 2.10 g of phosphorus pentachloride. The yield was 60 mol%. This product showed the following nuclear magnetic resonance spectrum.

δ(CD₃ OD) = 6.8 to 6.1 ppm (m, 3H), B 5.1 ppm (s, H), 4.4 (dt, 2H), 3.72 (d, 3H), 2.28 (dt, 2H).

Compounds Nos. 35, 36 and 37 of formula (1-a) were prepared in the same way as above.

EXAMPLE 7

By the same procedure as in Example 3, dimethyl 2-methanesulfonyloxyethylphosphonate was prepared from 15.4 g of dimethyl 2-hydroxyethylphosphonate, 39.5 g of pyridine and 11.5 g of methanesulfonyl chloride in a yield of 88 mol%.

Nuclear magnetic resonance spectrum (CDCl₃): δ=2.31 ppm (dt, 2H), 3.09 (s, 3H), 3.80 (d, 6H), 4.47 (dt, 2H).

13.9 g of the dimethyl 2-methanesulfonyloxyethylphosphonate was placed in a reactor and heated to 140 to 150° C. With stirring, 30.0 g of phosphorus pentachloride was added, and the reaction was performed for 20 minutes. The reaction mixture was cooled to room temperature, and a dry sulfurous acid gas was passed into the reaction mixture to oxidize the unreacted phosphorus pentachloride. The resulting by-products were distilled off at reduced pressure, and to the remaining oily liquid, 3.4 g of phosphorus pentasulfide was added. The mixture was heated to 120 to 130° C. for 2 hours, and extracted with 100 ml. of dry diethyl ether. The insoluble matter was separated by filtration, and the filtrate was concentrated at reduced pressure. The concentrate was dried in vacuo (0.1 mmHg) to afford 6.2 g of a brown oil in a yield of 41.2 mol%. This compound showed the following characteristic values, and was identified as Compound No. 47 of formula (1-b).

Infrared absorption spectrum (cm⁻¹): 3040, 2980, 2940, 1465, 1360, 1240,, 1180, 1050, 990, 960, 880, 800, 760, 720.

Nuclear magnetic resonance spectrum (CDCl₃): δ=3.15 ppm (s, 3H), 3.37 (dt, 2H), 4.75 (dt, 2H)

Refractive index: n_(D) ²⁵ = 1.4650

by the same procedure as above, Compound No. 48 of formula (1-b) was prepared. This product has a refractive index (n_(D) ²⁵° C) of 1.5536.

Example 8 2.2 g of the 2-methanesulfonyloxyethylthionophosphonyl dichloride obtained in Example 7 was cooled with ice, and with stirring, 2.0 g of water was added dropwise. After the addition, the mixture was warmed to 40° C., reacted for 1 hour, and concentrated at reduced pressure at room temperature. The residue was dissolved in a small amount of water, and a small amount of activated carbon was added. The mixture was stirred, and filtered. The mother liquor was concentrated at reduced pressure, and dried in vacuo (0.1 mmHg) to afford 1.4 g of a highly viscous liquid identified as Compound No. 49 of formula (1-b).

The product showed the following characteristic values, and was identified as Compound No. 49.

Infrared absorption spectrum (cm⁻¹): 3020, 2930, 2600, 2290, 2160, 1630, 1350, 1250, 1170, 1040-920, 790, 730.

Nuclear magnetic resonance spectrum (CD₃ OD): δ=2.33 ppm (dt, 2H), 3.11 (s, 3H), 4.45 (dt, 2H), 5.47 (s, 2H).

Refractive index n_(D) ²⁵ = 1.5075

by the same procedure as above, Compounds Nos. 50 and 52 of formula (1-b) were prepared. Compound No. 52 had a retractive index (n_(D) ²⁵° C) of 1.5450.

Example 9

2.2 g of 2-methanesulfonyloxyethylthionosphonic acid dichloride obtained in Example 7 was dissolved in 20 ml. of dry diethyl ether, and with stirring, 1.8 g of benzyl alcohol was added dropwise. Then, 0.8 g of pyridine was added dropwise with stirring under ice cooling. After the addition, the mixture was allowed to stand at room temperature for 1 week, and the resulting crystals were separated by filtration. The mother liquor was concentrated at reduced pressure, and dried in vacuo to afford 1.6 g of a viscous liquid identified as Compound No. 51 of formula (1-b).

By the same procedure as above, Compounds Nos. 53 to 56 of formula (1-b) were prepared.

Example 10

7.8 g of dimethyl 2-methanesulfonyloxyethylphosphonate was placed in a reactor, and heated to 140° to 150° C. With stirring, 16.8 g of phosphorus pentachloride was added, and the reaction was carried out for 20 minutes. The reaction mixture was cooled to room temperature, and a dry sulfurous acid gas was passed into the mixture to oxidize the unreacted phosphorus pentachloride. The resulting by-products were distilled off at reduced pressure. The residual oily liquid was dissolved in 60 ml. of dry methylene chloride, and the solution was cooled to -10° to -18° C. 21.3 g of p-chlorobenzenethiol and 11.1 g of pyridine were simultaneously added dropwise to this solution with stirring. After the addition, the solution was allowed to stand at 0° to 5° C. for 48 hours. The resulting crystals were separated by filtration, and the mother liquor was concentrated at reduced pressure to give a residual solid. 100 ml. of diethyl ether was added to the solid to extract a soluble matter. The ethereal phase was then concentrated at reduced pressure. The resulting solid was recrystallized from petroleum ether to afford colorless acicular crystals identified as Compound No. 57 of formula (1-c) in a yield of 30 mol%. This product had the following characteristic values.

Infrared absorption spectrum (cm⁻¹): 3040, 2960, 1595, 1490, 1410, 1338, 1180, 1165, 1100, 1040, 1020, 990, 960, 850, 720.

Nuclear magnetic resonance spectrum (CDCl₃) δ=2.50 ppm (dt, 2H), 3.02 (s, 3H), 4.15 (d, 4H), 4.40 (dt, 2H), 7.32 (s, 10H).

Melting point: 84° to 85.5° C.

by the same procedure as above, Compounds Nos. 58, 59, 60, 61, 62, 63 and 71 of formula (1-c) were prepared. Compound No. 58 had a melting point of 56 to 59° C., and Compound No. 60 had a refractive index (n_(D) ²⁵° C) of 1.6200.

Example 11

Compound No. 64 of formula (1-c) was prepared by the same procedure as in Example 7 from 7.6 g of dimethyl 2-methanesulfonyloxyethylphosphonate, 9.0 g of phosphorus pentachloride and 6.2 g of ethyl thiol. The yield was 48 mol%. This product showed the following characteristic values.

Infrared absorption spectrum (cm⁻¹): 3020, 2970, 2940, 1460, 1350, 1270, 1170, 1135, 1040, 940, 880, 810, 720.

By the same procedure as above, Compounds Nos. 65 and 72 of formula (1-c) were prepared.

Example 12

Compound No. 68 of formula (1-c) was prepared in the same way as in Example 1 from 2.3 g of dimethyl 2-methanesulfonyloxyethylphosphonate, 2.3 g of phosphorus pentachloride and 0.46 g of dimethylamine. The yield was 52 mol%. The IR spectrum of this product was as follows:

2980 cm⁻¹, 1360, 1250, 1180, 1030, 960-950

By the same procedure as above, Compound No. 69 of formula (1-c) was prepared.

Example 13

Compound No. 66 of formula (1-c) was prepared in the same way as in Example 1 from 3.3 g of dimethyl 2-(p-chlorobenzenesulfonyloxy)ethylphosphonate, 4.6 g of phosphorus pentachloride, 1.2 g of benzyl thiol and 0.2 g of water. By the same procedure as above, Compounds Nos. 67 and 70 of formula (1-c) were obtained.

Example 14

7.1 g of diethyl 2-methanesulfonyloxyethylphosphonate was heated to 145° C. With stirring, 14.2 g of phosphorus pentachloride was added, and they were reacted for 30 minutes. The mixture was cooled to room temperature. Sulfur dioxide gas was passed into the mixture, and the by-products were distilled at reduced pressure. 50 ml. of dry methylene dichloride was added to the residue to form a solution. The solution was cooled to -20° C., and 7.5 ml. of dry dimethylamine was passed into the solution. After allowing the solution to stand for 48 hours, the solvent was distilled at reduced pressure. Then, 50 ml. of dry ether was added, and the insoluble matter was filtered. The mother liquor was concentrated at reduced pressure, and dried in vacuo (0.7 mmHg) at room temperature to afford an oily liquid which was identified as Compound No.. 73 from the following characteristic values.

Infrared absorption spectrum: 2940 cm⁻¹, 1460, 1360, 1310, 1265, 1175, 990, 725.

Refractive index (n_(D) ¹³° C): 1.4623

Example 15

7.1 g of diethyl 2-methanesulfonyloxyethylphosphonate was heated to 145° C., and with stirring, 14.2 g of phosphorus pentachloride was added. The mixture was reacted for 30 minutes, and then cooled to room temperature. Sulfur dioxide gas was passed into the mixture, and the by-products were distilled off at reduced pressure. 50 ml. of dry methylene dichloride was added to the residue to form a solution. The solution was cooled to -20° C., and a solution of 11.3 g of aniline in 20 ml. of methylene dichloride was added dropwise. At 5° C., the mixture was allowed to stand for 48 hours. The resulting precipitate was separated by filtration. The mother liquor was concentrated at reduced pressure, and dried in vacuo (0.7 mmHg) at room temperature to afford a wax substance. This product was identified as Compound No. 74 from its infrared absorption spectrum.

Infrared absorption spectrum: 3040 - 2900 cm⁻¹, 1590, 1495, 1350, 1180 - 1120, 1020 - 930, 750, 690

Example 16

6.9 g of dimethyl 2-methanesulfonyloxyethylphosphonate was heated to 145° C., and with stirring 14.8 g of phosphorus pentachloride was added. They were reacted for 20 minutes. The reaction mixture was cooled to room temperature, and then sulfur dioxide was passed into the mixture. The by-products were distilled at reduced pressure. 50 ml. of methylene dichloride was added to the resulting residue to form a solution. 7.7 g of isopropylamine was added to the resulting methylene dichloride solution with cooling, and the mixture was allowed to stand at 5° C. for 48 hours. The resjlting precipitate was separated by filtration, concentrated at reduced pressure, and dried in vacuo to afford an oily liquid. This product was identified as Compound No. 75 from its infrared absorption spectrum and refractive index.

Infrared absorption spectrum: 3190 cm⁻¹, 2970, 1370, 1300, 1210, 1170, 1130, 1040, 930.

Refractive index (n_(D) ¹⁷° C): 1.4768.

Example 17

A solid product was prepared in the same way as in Example 16 from 5.9 g of dimethyl 2-methanesulfonyloxyethylphosphonate, 18.7 g of phosphorus pentachloride and 14.3 g of p-chloroaniline. This product was identified as compound No. 76 from its infrared absorption spectrum.

Infrared absorption spectrum: 2940 cm⁻¹, 1490, 1350, 1280, 1222, 1168, 1090, 940, 810.

Example 18

A viscous liquid was prepared in the same way as in Example 16 from 7.5 g of dimethyl 2-(p-toluenesulfonyl) oxyethylphosphonate, 12.2 g of phosphorus pentachloride and 8.6 g of isopropylamine. This product was identified as Compound No. 81 from its infrared absorption spectrum and refractive index.

Infrared absorption spectrum: 3240 cm⁻¹, 2970, 1595, 1460, 1360, 1300, 1170-1218, 1120, 1050, 1070, 815, 680

Refractive index (n_(D) ¹⁷° C): 1.5027

by the same procedure as above, Compounds Nos. 77 to 80, and 82 to 93 of formula (1-c) were prepared.

EXAMPLES OF FORMULATION AND APPLICATION (ALL PARTS ARE BY WEIGHT) Example 1 (liquid preparation)

A liquid preparation with an active ingredient concentration of 30% was prepared by mixing the following ingredients.

    ______________________________________                                         2-Methanesulfonyloxyethylthio-                                                 nophosphonate (Compound No. 49 of                                              formula (1-b)             30 parts                                             Ethanol                   30 parts                                             Propylene glycol          10 parts                                             Water                     25 parts                                             Polyoxyethylene dodecyl ether                                                                             5 parts                                             ______________________________________                                    

In use, the liquid preparation was diluted with water to the desired concentration, and sprayed.

Example 2 (liquid preparation)

A liquid preparation with an active ingredient concentration of 30% was prepared by uniformly mixing the following ingredients.

    ______________________________________                                         2-(2-carboxyethylsulfonyloxy)                                                  ethylphosphonic acid (Compound                                                 No. 8 of formula (1-a)    30 parts                                             Propylene glycol          25 parts                                             Ethyl alcohol             30 parts                                             Water                     10 parts                                             Alkylbenzenesulfonate as surfactant                                            (NEOGEN, a registered trademark of                                             Daiichi Kogyo Seiyaku K.K.)                                                                               5 parts                                             ______________________________________                                    

In use, the liquid preparation was diluted with water to the desired concentration, and sprayed.

Example 3 (emulsifiable concentrate)

An emulsifiable concentrate with an active inredient concentration of 40%) was prepared by mixing the following ingredients.

    ______________________________________                                         Dithio ester of S,S-diphenyl-2-                                                2-methanesulfonyloxyethyl-                                                     phosphonic acid (Compound No.                                                  58 of formula (1-c))      40 parts                                             Xylol                     50 parts                                             Sorpol 800 (trademark for polyoxy-                                             ethylene surfactant, made by                                                   Toho Chemical Co., Ltd.)  10 parts                                             ______________________________________                                    

In use, the emulsifiable concentrate was diluted with water to the desired concentration, and sprayed.

Example 4 (emulsifiable concentrate)

An emulsifiable concentrate with an active ingredient concentration of 50% was prepared by uniformly mixing the following ingredients.

    ______________________________________                                         Monoethyl 2-(3-thiocyanatopropyl-                                              sulfonyloxy)ethylphosphonate                                                   (Compound No. 14 of formula (1-a))                                                                       50 parts                                             Xylol                     40 parts                                             Sorpol 800                10 parts                                             ______________________________________                                    

In use, the emulsifiable concentrate was diluted with water to the desired concentration, and sprayed.

Example 5 (wettable powder)

A wettable powder with an active ingredient concentration of 30% was prepared by mixing the pulverizing the following ingredients.

    ______________________________________                                         2-(2-Carboxyethylethylsulfonyloxy)                                             ethylthionophosphonic acid                                                     (Compound No. 50 of formula (1-b))                                                                       30 parts                                             Mixture of equal amounts of talc                                               and clay                  65 parts                                             Sodium alkylbenzenesulfonate                                                                              3 parts                                             Sodium dinaphthylmethanedisulfonate                                                                       2 parts                                             ______________________________________                                    

In use, the wettable powder was diluted with water to the desired concentration.

Example 6 (wettable powder)

A wettable powder having an active ingredient concentration of 40% was prepared by mixing and pulverizing the following ingredients.

    ______________________________________                                         2-(2-Phthalimidoethylsulfonyloxy)                                              ethylphosphonic acid (Compound                                                 No. 17 of formula (1-a))  40 parts                                             Mixture of equal amounts of                                                    Zieklite and Kunilite                                                          (trademarks for fillers)  55 parts                                             Sodium alkylbenzenesulfonate                                                   as surfactant              3 parts                                             Sodium dinaphthylmethanedisulfonate                                                                       2 parts                                             ______________________________________                                    

In use, the wettable powder was diluted with water to the desired concentration.

Example 7 (paste)

A paste having an active ingredient concentration of 3% was prepared by mixing the following ingredients thoroughly.

    ______________________________________                                         Monomethyl 2-(3-bromopropylsulfonyl-                                           oxy)ethylsulfonate (Compound No. 1                                             of formula (1-a)           3 parts                                             Sorbitol                  20 parts                                             Sorbitan-long-chain fatty acid                                                 ester                     10 parts                                             Nineral oil               10 parts                                             Water                     57 parts                                             ______________________________________                                    

In use, the paste was applied in the desired amount.

Example 8 (emulsifiable concentrate)

    ______________________________________                                         Monoethyl 2-methanesulfonyloxy-                                                ethylphosphonate          50 parts                                             Xylol                     40 parts                                             Polyoxyethylene compound as a                                                  surfactant (Sorpol 800, a regis-                                               tered trademark of Toho Chemical                                               Co., Ltd.)                10 parts                                             ______________________________________                                    

The above ingredients were uniformly mixed to form an emulsifiable concentrate having an active ingredient content of 50%.

In use, the emulsifiable concentrate was sprayed after being diluted with water to the desired concentration.

    ______________________________________                                         2-Methanesulfonyloxyethylphos-                                                 phonic acid               30 parts                                             Propylene glycol          25 parts                                             Ethyl alcohol             30 parts                                             Water                     10 parts                                             Alkylbenzenesulfonate                                                          as a surfactant (NEOGEN,                                                       a trademark of Daiichi                                                         Kogyo Seiyaku K.K.)        5 parts                                             ______________________________________                                    

These ingredients were mixed uniformly to form a liquid preparation having an active ingredient content of 30%. In use, it was diluted to the desired concentration, and sprayed.

Example 10 (wettable powder)

    ______________________________________                                         2-Methanesulfonyloxyethylphosphonic                                            acid                      40 parts                                             Mixture of equal amount of Zieklite                                            and Kunilite as fillers (a trademark,                                          Kokuho Co., Ltd.)         55 parts                                             Sorpol 800                                                                     (a trademark for a surface                                                     active agent)              5 parts                                             ______________________________________                                    

The above ingredients were mixed, and pulverized to form a wettable powder having an active ingredient content of 40%. In use, the wettable powder was diluted to the desired concentration, and sprayed.

Example 11 (liquid preparation)

    ______________________________________                                         2-Methanesulfonyloxyethylphosphonic                                            acid bis(dimethylamide)   30 parts                                             Ethyl alcohol             30 parts                                             Propylene glycol          25 parts                                             Water                     10 parts                                             Alkylbenzenesulfonate (NEOGEN,                                                 a registered trademark, Daiichi                                                Kogyo Seiyaku K.K.)        5 parts                                             ______________________________________                                    

These ingredients were mixed uniformly to form a liquid preparation having an active ingredient content of 30%. In use, the liquid preparation was diluted to the desired concentration, and sprayed.

Example 12 (emulsifiable concentrate)

    ______________________________________                                         2-p-toluenesulfonyloxyethyl-                                                   phosphonic acid bis(isopropylamide)                                                                      50 parts                                             Xylol                     40 parts                                             Sorpol 800 (a registered trademark                                             for a polyoxyethylene as a surfac-                                             tance, Toho Chemical Co., Ltd.)                                                                          10 parts                                             ______________________________________                                    

The above ingredients were uniformly mixed to form an emulsifiable concentrate having an active ingredient of 50%. In use, the emulsifiable concentrate was diluted with water to the desired concentration, and sprayed.

Example 13 (wettable powder)

    ______________________________________                                         2-Methanesulfonyloxyethylphosphonic                                            acid bis(dimethylamide)   40 parts                                             Mixture of equal amounts of Zieklite                                           and Kunilite as fillers   55 parts                                             Sorpol 800 (surfactant)    5 parts                                             ______________________________________                                    

The above ingredients were mixed and pulverized to form a wettable powder having an active ingredient content of 40%. In use, it was diluted to the desired concentration and sprayed.

Example 14 (paste)

    ______________________________________                                         2-Methanesulfonyloxyethylphosphonic                                            acid bis(isopropylamide)   2 parts                                             Bentonite                 25 parts                                             Starch                    33 parts                                             Vaseline                  20 parts                                             ______________________________________                                    

The above ingredients were mixed well with water to form a paste having an active ingredient content of 2%.

Test Example 1

Test for swelling of young garden peas

Pots with an inside diameter of 9 cm were filled with a field soil of valcanic ashes. Fifteen seeds of garden pea were sown in each pot, and grown for one week in a constant temperature chamber (dark place) at 25° C. 2 ml. of the wettable powder of this invention diluted with water to each of the concentrations shown in Table 1 was sprayed uniformly over the upper ground of garden peas grown to a height of 5 to 7 cm. These plants were placed in a dark room at 25° C., and the extent of swelling of the stem of the peas was evaluated on the following scale. The results are shown in Table 1.

                                      Table 1                                      __________________________________________________________________________     (The results of the swelling test on garden peas)                              Concent-                                                                       ration                                                                              Compound                                                                  (ppm)                                                                               No. 1 No. 2                                                                               No. 3                                                                               No. 4                                                                              No. 5                                                                              No. 6                                                                               No. 7                                                                               No. 8                                                                               No. 9                                                                              No. 10                                                                             No.                                                                                 No.                   __________________________________________________________________________                                                              12                    8,000                                                                               +++   +++  +++  +++ ++  ++   +++  +++  +++ ++  ++   ++                                                                    ˜+++                     4,000                                                                               ++    ++˜                                                                           ++   ++˜                                                                          ++  ++   ++˜                                                                           ++˜                                                                           ++  ++  ++   +                                +++  ˜+++        +++  +++                                     2,000                                                                               +     +    +    +   +   +    ++   ++   ++  +   +    +                     1,000                                                                               +     +    +    +   ±                                                                               ± +    +    +   +   +    ±                  __________________________________________________________________________     Concent-                                                                       ration                                                                         (ppm)                                                                               No. 13                                                                               No. 14                                                                              No. 15                                                                              No. 16                                                                             No. 17                                                                             No. 18                                                                              No. 19                                                                              No. 20                                                                              No. 21                                                                             No. 22                                                                             No.                                                                                 No.                   __________________________________________________________________________                                                              24                    8,000                                                                               ++    ++   ++˜                                                                           ++  ++  ++   +++  ++   +++ +++ ++   ++                                    +++                                                            4,000                                                                               +     +    ++   +   ++  +    ++   +    ++  ++  +    +                     2,000                                                                               ±  +    +    +   +   +    +    +    +   +   +    +                     1,000                                                                               ±  ±˜+                                                                        ± ±                                                                               +   ± +    ± +   +   ± ±                  __________________________________________________________________________     Concent-                                                                       ration                                                                         (ppm)                                                                               No. 25                                                                               No. 26                                                                              No. 27                                                                              No. 31                                                                             No. 32                                                                             No. 33                                                                              No. 34                                                                              No. 35                                                                              No. 47                                                                             No. 48                                                                             No.                                                                                 No.                   __________________________________________________________________________                                                              50                    8,000                                                                               ++˜                                                                            ++   +++  ++  ++  ++˜                                                                           ++   ++   ++  ++  +++  +++                        +++                     +++                                               4,000                                                                               ++    ++   ++   ++  +˜++                                                                         ++   +    ++   +   +   ++˜                                                                           ++                                                                        +++                        2,000                                                                               +     +˜±                                                                        ++   +   +˜±                                                                       +    ± +    ±                                                                               +   ++   +˜++            1,000                                                                               +˜±                                                                         +˜±                                                                        +    +   ±                                                                               ± ± +    ±                                                                               ±                                                                               +    +                     __________________________________________________________________________                                                         Control                                                                        (2-chloro-                                                                     roethyl-                                                                            β-hydro-         Concent-                                            phos-                                                                               xyethyl-              ration                                              phonic                                                                              hydra-                (ppm)                                                                               No. 52                                                                               No. 53                                                                              No. 57                                                                              No. 59                                                                             No. 60                                                                             No. 62                                                                              No. 63                                                                              No. 64                                                                              No. 65                                                                             No. 66                                                                             acid)                                                                               zine                  __________________________________________________________________________     8,000                                                                               ++    ++˜                                                                           +˜++                                                                          ++  +˜++                                                                         ++˜                                                                           +++  +++  ++  ++  +++  ±                             +++               +++                                               4,000                                                                               +     +    ±˜+                                                                        +   +   --   ++   ++˜                                                                           +   +   ++   -                                                            +++                                     2,000                                                                               ±  ±˜+                                                                        ± ±                                                                               +   +    +    ++   +   ±                                                                               +    -                     1,000                                                                               ±  ± ± ±                                                                               ±                                                                               +    +    +    ±                                                                               ±                                                                               +    -                     __________________________________________________________________________      -: the rate of swelling on the basis of the non-treated lot being less         than 5%                                                                        ±: the rate of swelling 6 to 20%                                            +: the rate of swelling 21 to 40%                                              ++: the rate of swelling 41 to 60%                                             +++: the rate of swelling 61 to 80%                                            ++++: the rate of swelling 81 to 100%                                    

Test Example 2

Pots with an inside diameter of 12 cm were filled with a field soil of volcanic ashes. Uniformly grown tomatoes (10 leaves) were transplanted in each of the pots. The pots were then allowed to stand in a greenhouse, and after the tomatoes set their roots firmly, the paste of the compound of this invention was coated on an aluminum foil in an amount of 0.1g or 0.05 g and applied to the fifth internode of the tomato plants. Five days after the application, the degree of epinasty was evaluated.

                  Table 2                                                          ______________________________________                                                     Amount      Angle between the                                      Compound Nos.                                                                              applied (g) petiole and the stem                                   ______________________________________                                         7           0.1         115°                                                        0.05        82°                                             8           0.1         124°                                                        0.05        90°                                             21          0.1         114°                                                        0.05        76°                                             49          0.1         110°                                                        0.05        77°                                             2-Chloroethyl-                                                                             0.1         112°                                            phosphonic acid                                                                            0.05        80°                                             Non-treated             56°                                             ______________________________________                                    

Test Example 3

Pots with an inside diameter of 12 cm were filled with a field soil of volcanic ashes, and uniformly grown tomatoes (10 grown leaves) were transplanted in each pot. The pots were allowed to stand in a greenhouse, and after they fully took roots, the wettable powder of the compound of this invention was dissolved in water to form dilutions with the desired concentration. 3 ml. of each of the dilutions was sprayed uniformly on the leaves and the stalk. Then, the tomatoes were grown for 20 days in a greenhouse, and the epinasty of the tomatoes, the action of forming adventitious roots, the defoliating action, and phytotoxicity were examined. The evaluation of the results was made on a scale of the following five grades.

                                      Table 3                                      __________________________________________________________________________     Effects of treatment on tomatoes                                                                         Formation of                                                      Concentration                                                                               adventitious                                         Compound     (ppm)   Epinasty                                                                            root   Defoliation                                                                           Phytotoxicity                          __________________________________________________________________________     7            8,000   +++  +++    ++     -                                                   4,000   +++  ++     +      -                                                   2,000   ++   +      +      -                                                   1,000   +    +      ±   -                                      8            8,000   +++  ++     +      -                                                   4,000   +++  ++     ±˜+                                                                          -                                                   2,000   ++   +      ±   -                                                   1,000   +    ±   -      -                                      21           8,000   ++   ++     +      -                                                   4,000   ++   ++     ±   -                                                   2,000   +    +      ±   -                                                   1,000   +    ±   -      -                                      2-chloroethylphosphonic                                                                     8,000   +++  +++    + +    ±                                   acid (comparison)                                                                           4,000   ++   +++    +      ±                                                2,000   +    ++     ±˜+                                                                          -                                                   1,000   +    +      ±   -                                      β-hydroxyethylhydrazine                                                                8,000   +    ±   +      -                                      (comparison) 4,000   -    -      -      -                                      __________________________________________________________________________      -: non-phytotoxicity                                                           ±: slight                                                                   +: moderate                                                                    ++: extreme                                                                    ++⃡: severe                                                  

Example 4

Unglazed pots with an inside diameter of 15 cm were filled with a field soil of volcanic ashes, and 12 French bean seeds were sown in each of the pots. Then, they were grown for about one week in a greenhouse. Eight uniformly grown plants were left, and the others were cut off by a scissors. When the second triple leaflets of the French beans were developed, the leaves and the stalk of the French beans were sprayed with 4 ml. of the wettable powder of the chemical of this invention diluted with water to each of the concentrations shown in Table 4. The evaluation was made on the same scale of five grades as in Test Example 1.

                                      Table 4                                      __________________________________________________________________________     Effects on French beans                                                                          Growth                    Disappearance                               Concentration                                                                           inhibi-                   of apical                          Compounds                                                                               (ppm)    tion  Epinasty                                                                              Yellowing                                                                            Defoliation                                                                           dominance                          __________________________________________________________________________              4,000   ++˜+++                                                                          +++    +++   +++    +++                                49       2,000   +      ++˜+++                                                                          ++    ++     ++                                          1,000   +      +      +     +      +                                           4,000   ++˜+++                                                                          +++    +++   +++    +++                                50       2,000   ++     ++˜+++                                                                          ++    +˜++                                                                            ++                                          1,000   +      +      +     +      +˜++                                  4,000   ++     ++     ++    +      ++                                 52       2,000   +      ++     +     ±   +                                           1,000   ±   +      ±  ±   +                                           4,000   +++    +++    +++   +++    +++                                63       2,000   ++     ++     +˜++                                                                           ++     ++                                          1,000   +      ++     +     +˜++                                                                            +˜++                         2-Chloroethyl-                                                                          4,000   +++    +++    +++   +++    +++                                phosphonic acid                                                                         2,000   ++     ++     ++    ++     ++                                 (comparison)                                                                            1,000   ++     +      +     ++     -                                  β-hydroxyethyl-                                                                    8,000   ±   +      +     ±   ±                               hydrazine                                                                               4,000   -      ±   ±  -      -                                  (comparison)                                                                            2,000   -      -      -     -      -                                  __________________________________________________________________________

Test Example 5

The wettable powder of this invention diluted with water to each of the concentrations shown in Table 5 was sprayed to the stalk and leaves of uniformly grown tabacco plants after 80 days from sowing and before flowering. The amount of the water diluted powder sprayed was 10 ml. per plant. The tobaccoes were then grown in a greenhouse, and three days after the treatment, the rate of falling of the tobacco flower buds was determined. Twenty days after the treatment, the degree of yellowing of the tobacco leaves was determined. The results are shown in Table 5.

                  Table 5                                                          ______________________________________                                         Treatment effect on tobaccoes                                                           Concentration                                                                               Rate of falling                                                                             Yellowing                                   Compounds                                                                               (ppm)        flower buds (%)                                                                             degree (%)                                  ______________________________________                                                  2,000        100          80                                          3        1,000        100          50                                                   500          100          40                                                   2,000        100          80                                          7        1,000        100          62                                                   500          100          50                                                   2,000        100          82                                          8        1,000        100          50                                                   500          100          34                                                   2,000        100          60                                          21       1,000        80           40                                                   500          40           20                                                   2,000        100          74                                          49       1,000        100          53                                                   500          95           23                                                   2,000        100          65                                          63       1,000        86           42                                                   500          62           24                                          2-Chloro-                                                                               2,000        100          80                                          ethylphos-                                                                     phonic acid                                                                             1,000        82           60                                          (Comparison)                                                                            500          54           32                                          BOH      2,000        44           40                                          (Comparison)                                                                            1,000        16           13                                                   500          5            8                                           Non-treated                                                                             0            0            7.5                                         ______________________________________                                    

Test Example 6

Coloration Test on Oranges

Mandarine oranges (Unshu variety) having a color resembling the bright color of the lower back of a firefly were coated with 2 ml. of each of water-diluted emulsions of this invention in each of the concentrations shown in Table 6, and allowed to stand in a constant temperature chamber at 10° C. On the tenth day after the treatment, the degree of coloration was observed. The test results were indicated as average values of five oranges in each lot. The evaluation was made on the following scale. The results are shown in Table 6.

                                      Table 6                                      __________________________________________________________________________     Promotion of the coloration of oranges                                         Concentration                                                                          Compound                                                               (ppm)   No. 3                                                                               No. 7                                                                               No. 8                                                                               No. 14                                                                              No. 21                                                                              No. 49 No. 50                                 2,000   5    5    5    4.5  5    5      5                                      1,000   4.5  5    5    3.5  4.5  5      5                                      500     4    4.5  4.5  3.5  4    4      4.5                                                                            β-Hydro-                                                           2-Chloro-                                                                             xyethyl-                                                                ethylphos-                                                                            hydrazine                              Concentration                    phonic acid                                                                           (compari-                                                                            Non-                             (ppm)   No. 63                                                                              No. 33                                                                              No. 27                                                                              No. 69                                                                              No. 70                                                                              (comparison)                                                                          son)  treated                          2,000   5    5    5    5    5    5      3     1.5                              1,000   5    4.5  4.5  4    4    4      2                                      500     4    4    4    3.5  3.5  3.5    1.5                                    __________________________________________________________________________      0: Coloration before the treatment                                             1: Colored 20%                                                                 2: Colored 40%                                                                 3: Colored 60%                                                                 4: Colored 80%                                                                 5: Completely colored                                                    

Test Example 7

50 ml. of an aqueous solution of the emulsifiable concentrate of this invention in each of the concentrations indicated in Table 7 was sprayed uniformly all over the stalk and leaves of 3-year old nut trees (1.5 m high). Fifteen days after the treatment, the degree of defoliation was examined. The results are shown in Table 7.

                  Table 7                                                          ______________________________________                                                   Concentration (ppm)                                                  Compounds Nos.                                                                             10,000     5,000      2,500                                        ______________________________________                                         3           100        85         65                                           8           100        100        70                                           14          100        80         60                                           21          100        80         75                                           49          98         60         30                                           63          100        62         40                                           Comparison* 100        70         52                                           Comparison**                                                                               5          0          0                                            ______________________________________                                           *2-Chloroethylphosphonic acid                                                  **β-hydroxyethylhydrazine                                          

Test Example 8

A 10% w/v solution of the chemical of this invention in a coconut oil was coated on the leaves of a 3-year old Ficus elastica tree. Two days later, the coated leaf blades were cut at the site of the petiole. The latex oozing out from the cuts was allowed to penetrate in a filter paper whose weight had been measured. The filter paper was then dried in the air, and its weight was measured. The yield of the latex obtained from ten leaves with respect to each concentration was divided by the weight of the leaves, and expressed is percentages based on the value obtained with the nontreated group. The results are shown in Table 8.

                  Table 8                                                          ______________________________________                                         Compounds Nos.      Percentages                                                ______________________________________                                         3                   132                                                        7                   140                                                        8                   153                                                        21                  135                                                        49                  138                                                        63                  134                                                        2-Chloromethylphos-                                                            phonic acid         139                                                        Non-treated         100                                                        ______________________________________                                    

Test Example 9

A 10% w/v solution of the chemical of this invention in a coconut oil was coated in a tape form with a width of 5 cm immediately below an extracting cut provided on the trunk of Hevea brasiliensis. Every other day, an extracting cut in a semi-helical shape was provided, and the yield of dry rubber obtained over a period of two weeks was measured. The results are shown in Table 9. The values in the table are percentages based on the control (coating of a coconut oil alone).

                  Table 9                                                          ______________________________________                                         Compounds Nos.      Percentages                                                ______________________________________                                         3                   145                                                        7                   152                                                        8                   162                                                        49                  150                                                        2-Chloromethylphos-                                                            phonic acid         156                                                        Coconut oil         100                                                        ______________________________________                                    

Test Example 10

The swelling test on young garden peas was performed in the same way as in Test Example 1 except that the amount of the chemical applied to the leaves and the stalk was changed to 1 ml. in the concentration shown in Table 10. The results were evaluated on a scale of five grades as follows:

                                      Table 10                                     __________________________________________________________________________                 Test Chemicals (Compounds Nos)                                                                                       2-Chloro-                                                                      ethyl-                                                                         sulfonic                     Concentra-                                        acid                         tion                                              (compa-                      (mol/l)     No. 38                                                                             No. 39                                                                             No. 40                                                                             No. 41                                                                              No. 42                                                                             No. 43                                                                             No. 44                                                                             No. 45                                                                              No. 46                                                                             rison)                       __________________________________________________________________________     5 × 10.sup.-2                                                                        +++ ++  ++  +˜++                                                                          ++  +++ ++  +˜++                                                                          ++  +++                          2.5 × 10.sup.-2                                                                      +++ ++  +   +    +   +++ +   +    +   +++                          10.sup.-2   ++  +   +   +    +   ++  +   ± ±                                                                               ++                           5 × 10.sup.-3                                                                        ++  ±                                                                               ±                                                                               ± ±                                                                               +   ±                                                                               ± ±                                                                               +                            10.sup.-3   +   ±                                                                               ±                                                                               ± ±                                                                               +   ±                                                                               -    -   ±                         __________________________________________________________________________      -: no action                                                                   ±: small effect                                                             +: intermediate effect                                                         ++: somewhat great effect                                                      +++: very great effect                                                   

Test Example 11

The effects on tomatoes were tested in the same way as in Test Example 3 by using the chemicals in the concentrations shown in Table 11. The results are shown in Table 11.

                                      Table 11                                     __________________________________________________________________________                            Formation of                                                      Concentration                                                                               adventitious                                            Chemicals (mol/l) Epinasty                                                                            root   leaf fall                                                                            Phytotoxicity                              __________________________________________________________________________               5 × 10.sup.-2                                                                    +++  +++    ++    -                                          Compound No. 38                                                                          10.sup.-2                                                                              +++  ++     +     -                                                    5 × 10.sup.-3                                                                    ++   +      +     -                                                    10.sup.-3                                                                              +    +      ±  -                                                    5 × 10.sup.-2                                                                    ++   ++     +     -                                          Compound No. 41                                                                          10.sup.-2                                                                              ++   +      ±  -                                                    5 × 10.sup.-3                                                                    +    +      ±  -                                                    10.sup.-3                                                                              ± ±   -     -                                          2-Chloroethyl-                                                                           5 × 10.sup.-2                                                                    +++  +++    ++    +                                          phosphonic                                                                               10.sup.-2                                                                              ++   +++    +     ±                                       acid      5 × 10.sup.-3                                                                    +    ++     ±  -                                          (comparison)                                                                             10.sup.-3                                                                              ± +      ±  -                                          __________________________________________________________________________

Example 12

The effects on tobacco plants were tested in the same way as in Test Example 5 by using the chemicals in the concentrations shown in Table 12. The results are shown in Table 12.

                  Table 12                                                         ______________________________________                                                                          Yellowing rate                                          Concent- Falling of flower                                                                            (%) (20 days                                            ration   buds (%) (one day                                                                            after treat-                                  Test Chemicals                                                                           (mol/l)  after treatment                                                                              ment)                                         ______________________________________                                         Compound  10.sup.-2                                                                               100           75                                            No. 38    10.sup.-3                                                                               100           50                                                      10.sup.-4                                                                               100           40                                            Compound  10.sup.-2                                                                               100           60                                            No. 41    10.sup.-3                                                                               95            40                                                      10.sup.-4                                                                               60            25                                            Compound  10.sup.-2                                                                               100           75                                            No. 43    10.sup.-3                                                                               100           50                                                      10.sup.-4                                                                               90            40                                            Compound  10.sup.-2                                                                               100           50                                            No. 44    10.sup.-3                                                                               75            30                                                      10.sup.-4                                                                               40            20                                            2-Chloro- 10.sup.-2                                                                               100           75                                            ethylphos-                                                                               10.sup.-3                                                                               85            60                                            phonic acid                                                                              10.sup.-4                                                                               50            30                                            (comparison)                                                                   ______________________________________                                    

Test Example 13

Tomatoes, ripe but not yet colored, were harvested, and the wettable powders of this invention diluted with water to the concentrations shown in Table 13 were coated in an amount of 2 ml. on the skins of the tomatoes. The coated tomatoes were allowed to stand indoors for 10 days, and then the degree of coloration was determined. The results are shown in Table 13.

                  Table 13                                                         ______________________________________                                                Chemicals                                                               Concentra-                   2-Chloroethylphos-                                tion     Compound  Compound  nonic acid                                        (mol/l)  No. 38    No. 41    (comparison)                                      ______________________________________                                         10.sup.-2                                                                                +++      +++       +++                                               5 × 10.sup.-3                                                                     ++        ++        +                                                 10.sup.-3                                                                               ++        +         ±                                              ______________________________________                                    

Test Example 14

One week before the full flowering of persimmons (variety Fuyu), an aqueous solution each of the wettable powder of this invention and 2-chloroethylphosphonic acid (comparison) was sprayed in the concentration given in Table 14 to all over the trees. The test results were investigated 20 days after the treatment, and the fruit-bearing rate and the fruit-to-leaf ratio were determined. The results are shown in Table 14. The fruit-to-leaf ratio shows the balance between the number of leaves and the number of fruits, and indicates the number of fruits per leaf.

                  Table 14                                                         ______________________________________                                                                Fruit-                                                              Concentra- bearing   Fruit-to-leaf                                 Chemicals   tion (ppm) rate (%)  ratio                                         ______________________________________                                         Compound No. 38                                                                            30         25.2      20.1                                                      50         21.8      23.5                                                      75         13.8      30.6                                          2-Chloroethyl-                                                                             30         38.0      13.8                                          phosphonic acid                                                                            50         26.2      16.1                                          (Comparison)                                                                               75         23.4      20.2                                          Non-treated                                                                    (comparison)           39.2      13.0                                          ______________________________________                                    

These results demonstrate that the chemical of this invention can lead to fruit harvesting to a degree near the ideal fruit-to-leaf ratio (20 to 25) in the cultivation of Fuyu persimmons, and can markedly save the labor of picking fruits.

Test Example 15

An aqueous solution of the liquid preparation of this invention in each of the concentrations indicated in Table 15 was sprayed all over the stem and leaves of pineapples (variety, Singapore Spanish) in an amount of 50 ml. per pineapple plant. 50 days after the treatment, the rate of flowering (the number of pineapples taking flowers to that of pineapples treated) was determined. Ten pineapples were grown per lot. The results are shown in Table 15.

                  Table 15                                                         ______________________________________                                                    Concentra- Rate of   Average fruit                                  Chemicals  tions (ppm)                                                                               flowering weight (g)                                     ______________________________________                                         Compound No.                                                                              200        10/10     850                                              41       400        10/10     903                                                       800        10/10     905                                            2-Chloroethyl-                                                                            200         7/10     840                                            phosphonic 400         9/10     850                                            acid       800        10/10     900                                            (comparison)                                                                   Carbide    Conventional                                                        (comparison)                                                                              method      6/10     780                                            ______________________________________                                    

Test Example 16

Mandarine oranges (variety, Unshu) having a color resembling the bright color of the lower back of a firefly were immersed for 3 minutes in an aqueous solution of the emulsifiable concentrate of this invention in each of the concentrations shown in Table 16, withdrawn, and then allowed to stand indoors for 5 hours. Then, they were thoroughly washed with water, and dried in air. Ten days after the treatment, the acidity of the orange was measured, and the state of coloration was observed. The test results were expressed as average values of five oranges in one lot. The state of coloration was evaluated on the same scale as in Test Example 6.

                  Table 16                                                         ______________________________________                                                      Concentra- Acidity   State of                                     Chemicals    tion (ppm) (pH)      coloration                                   ______________________________________                                         Compound No. 41                                                                              500       3.45      4.5                                                       1000       3.48      5                                                         2000       3.60      5                                            2-Chloroethyl-                                                                               500       3.46      3.5                                          phosphonic acid                                                                             1000       3.45      4                                            (comparison) 2000       3.50      5                                            Non-treated                                                                    (comparison)            3.40      2.5                                          ______________________________________                                    

Test Example 17

Cucumbers (variety, Otone No. 1) in the four-leaf stage were sprayed at their stem and leaves with 10 ml. of an aqueous solution each of the wettable powders of this invention in the concentrations shown in Table 17, and were grown in a greenhouse. The percentage of the number of pistils which adhered based on the total number of flowers was examined. The results were expressed as averages of four pieces per lot. The results are shown in Table 17.

                  Table 17                                                         ______________________________________                                                                    Rate of                                                                               Rate of                                                                 pistil pistil                                                         Rate of  adhesion                                                                              adhesion                                                       pistil   at the at the                                                         adhesion 1st node                                                                              2nd node                                                       at the   of the of the                                                Concent- main     side   side                                                  ration   branch   branch branch Yield                                 Chemicals                                                                               (ppm)    (%)      (%)    (%)    ratio                                 ______________________________________                                         Compound 200      50.3     66.4   35.2   140                                   No. 38   100      38.4     62.0   32.5   130                                             50      20.5     57.0   20.4   130                                   Compound 200      45.3     64.6   31.5   120                                   No. 41   100      38.6     60.5   30.3   108                                             50      18.2     57.0   20.6   105                                   2-Chloro-                                                                               200      44.8     65.6   32.4   135                                   ethyl-                                                                         phosphonic                                                                              100      38.5     60.3   30.5   105                                   acid                                                                           (compari-                                                                                50      15.0     56.4   20.7   103                                   son)                                                                           Non-treated                                                                    (compari-          7.6     88.6    4.5   100                                   son)                                                                           ______________________________________                                    

Test Example 18

An aqueous solution of the emulsifiable concentrate of this invention in each of the concentrations shown in Table 18 was sprayed all over the stems leaves of a chestnut tree (3 years old; 1.0 to 1.5 m in height) in an amount of 50 ml. and of a small-sized persimmon trees in an amount of 5 ml. Fifteen days after the treatment, the rate of leaf falling was examined. The rate of leaf falling of 100% means that all the leaves fell, and the rate of leaf falling of 0% means that no leaf fell. The results are shown in Table 18.

                  Table 18                                                         ______________________________________                                                          Rate of leaf falling                                                           (%)                                                                       Concentra-           Small-sized                                   Chemicals   tion (ppm) Chestnut  persimmon                                     ______________________________________                                         Compound No. 38                                                                            10000      100       100                                                       5000       60        85                                                        2500       35        50                                            2-Chloroethyl-                                                                             10000      85        100                                           phosphonic acid                                                                            5000       50        60                                            (comparison)                                                                               2500       20        45                                            ______________________________________                                    

Test Example 19

The swelling test on young garden peas was performed in the same way as in Test Example 10 using the chemicals in the concentrations given in Table 19. The results are shown in Table 19.

                  Table 19                                                         ______________________________________                                         Chemicals                                                                      Con-    Com-     Com-     Com-   Com-   Com-                                   centra- pound    pound    pound  pound  pound                                  tion (ppm)                                                                             No. 73   No. 74   No. 75 No. 76 No. 81                                 ______________________________________                                         10,000  +++      ++       +++    ++     ++                                     5,000    ++      +        +++    +      +                                      2,500   +        ±      ++    +      ±                                   1,000   +        ±     +      ±   -                                      ______________________________________                                    

Test Example 20

Pots with an inside diameter of 12 cm were filled with a field soil of valcanic ashes, and uniformly grown French beans (with vines) were transplanted, two in each pot. The pots were allowed to stand in a greenhouse, and after the French bean plants took root, the wettable powder of this invention diluted with water to each of the concentrations shown in Table 20 was uniformly sprayed to the stalks and leaves of the plants in an amount of 2 ml. The plants were then grown for 10 days in the greenhouse, and then the epinasty, yellowing and leaf falling of the plants were observed. The evaluation of the effect was expressed on the same scale as in Test Example 10, and the phytotoxicity was evaluated on the same scale as in Test Example 3. The results are shown in Table 20.

                  Table 20                                                         ______________________________________                                                  Concent-                                                                       ration            Yellow-                                                                               Leaf  Phyto-                                 Chemical (ppm)    Epinasty ing    fall  toxicity                               ______________________________________                                         Compound 8,000    +++      ++     ++    -                                      No. 73   4,000    ++       +      +     -                                               2,000     +       ±   +     -                                      Compound 8,000    +++      ++     ++    -                                      No. 75   4,000    ++       +      +     -                                               2,000    ++       ±   +     -                                      2-Chloro-                                                                               8,000    +++      ++     ++    +                                      ethyl-                                                                         phospho- 4,000    +++      +      ++    ±                                   nic acid                                                                       (compari-                                                                               2,000    ++       +      +     -                                      son)                                                                           ______________________________________                                    

Test Example 21

The test on tobacco plants were performed in the same way as in Example 5. The results are shown in Table 21.

                  Table 21                                                         ______________________________________                                                            Falling of                                                                     flower buds                                                                    (%) one day Yellowing rate                                           Concentra-                                                                               after the   (%) 20 days                                     Chemicals                                                                               tion (ppm)                                                                               treatment   after treatment                                 ______________________________________                                         Compound 4000      100         70                                              No. 73   2000      80          40                                                       1000      60          20                                              Compound 4000      100         70                                              No. 75   2000      65          35                                                       1000      40          20                                              Non-treated                                                                             --        0           0                                               ______________________________________                                    

Test Example 22

The coloration test on mandarine oranges was performed in the same way as in Test Example 6 using each of the compounds shown in Table 22 in the concentrations indicated. The results are shown in Table 22.

                  Table 22                                                         ______________________________________                                                    Concentration                                                                               Acidity   State of                                     Chemicals  (ppm)        (pH)      coloration                                   ______________________________________                                         Compound   4000         3.50      5                                            No. 73     2000         3.48      4.5                                                     1000         3.60      4.5                                          Compound   4000         3.46      5                                            No. 75     2000         3.60      5                                                       1000         3.50      4.5                                          2-Chloroethyl-                                                                            4000         3.50      5                                            phosphonic 2000         3.60      5                                            acid       1000         3.55      4.5                                          (comparison)                                                                   Non-treated                                                                               --           3.60      2.5                                          ______________________________________                                    

Test Example 23

The effect of accelerating the leaf falling of chestnuts was tested in the same way as in Test Example 18 using each of the compounds shown in Table 23 in the concentrations indicated. The results are shown in Table 23.

                  Table 23                                                         ______________________________________                                                      Concentra-   Rate of leaf                                         Chemicals    tion (ppm)   falling (%)                                          ______________________________________                                         Compound     5000         50                                                   No. 73       2500         30                                                   Compound     5000         65                                                   No. 75       2500         40                                                   2-Chloro-    5000         60                                                   ethylphos-                                                                     phonic acid  2500         40                                                   (comparison)                                                                   Non-treated  --           0                                                    ______________________________________                                     

What we claim is:
 1. A compound of the formula ##STR58## wherein R₁ is a member selected from the group consisting of substituted or unsubstituted C₁ to C₁₂ linear- or branched-alkyl, C₅ to C₁₂ cyclo-alkyl, substituted or unsubstituted C₂ to C₁₂ linear- or branched-alkenyl or C₅ to C₁₂ cycloalkenyl and substituted or unsubstituted C₆ to C₁₄ carbocyclic aryl; at least one of R₂ and R₃ is morpholino and the other is selected from the group consisting of (1) --OR' in which R' is a member selected from the group consisting of a hydrogen atom, substituted or unsubstituted C₁ to C₁₂ linear- or branched-alkyl or C₅ to C₁₂ cyclo-alkyl, substituted or unsubstituted C₂ to C₁₂ linear- or branched-alkenyl or C₅ to C₁₂ cyclo-alkenyl and substituted or unsubstituted C₆ to C₁₄ carbocyclic aryl, (2) --SR' in which R' is as defined above, (3) --N(R')₂ in which R' is the same as defined above or the R' groups together with the nitrogen to which they are attached form morpholino, and (4) a halogen atom; and X is S or O; the substituent for the substituted alkyl group or the substituted alkenyl group is a member selected from the group consisting of halogen atoms, cyano, nitro, alkoxycarbonyl with the alkoxy moiety containing 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, carboxyl, alkanoyl of 1 to 12 carbon atoms, alkanoyloxy of 1 to 12 carbon atoms, benzoyloxy, thiocyanato, isothiocyanato, acetamide, acetylthio, phosphono, β-phosphonoethyloxysulfonyl, (CH₃)₃ ⁺ N^(C1-) CH₂ --CH₂ --, phenyl, phenylalkyl of 7 to 14 carbon atoms, and alkylthio with the alkyl moiety containing 1 to 12 carbon atoms; and with the substituent for the substituted aryl group is a member selected from the group consisting of alkyl of 1 to 6 carbon atoms, halogen atoms, acetyl, acetamido, nitro, cyano, carboxyl, alkoxy of 1 to 6 carbon atoms and hydroxyl; with the proviso that when X is S, both R₂ and R₃ are not the groups morpholino or --N(R')₂ at the same time.
 2. A method for regulating the growth of plants which comprises applying to a plant or to the locus in which a plant is growing or is to be grown a plant growth regulating amount of a compound according to claim
 1. 3. A plant growth regulating composition which comprises a plant growth regulating amount of a compound according to claim 1 and a gaseous, liquid or solid diluent therefor.
 4. A plant growth regulator composition of claim 26 which consists of about 0.00001% to about 99%, based on the weight of the regulator, of said compound of claim 1 and a gaseous, liquid or solid diluent therefor.
 5. A method according to claim 2 wherein the amount of said compound to be applied to the plant is 2 to 100 ml. per plant with the regulator concentration of about 10 to 10,000 ppm.
 6. A method according to claim 2 wherein the amount of said compound to be applied to the locus in which the plant is growing or will be grown is about 10 to 4,000 g/10 ares.
 7. A method according to claim 2 wherein the application of the compound to the plant is performed by immersing the plant in a liquid preparation of the compound in a concentration of about 10 to about 10,000 ppm. for a period of from about 3 minutes to about 6 hours. 